ABSTRACT
Background C57BL/6.NOD-Aec1Aec2 mouse is considered to be an idea model for the study of the pathogenesis of Sj(o)gren syndrome,but the cause of dry eye in these mice is unclear.Objective This study was to investigate the histopathological change of the ocular surfaces of C57BL/6.NOD-Aec1Aec2 mice,and to determine whether dry eye is developed spontaneously in these mice.Methods Forty-five clean C57BL/6.NOD-Aec1 Aec2 mice were used as the experiment group and forty-five C57BL/6J mice(both male and female)were used as the control group in this study.Detection of fasting blood-glucose,Schirmer' s test Ⅰ (S Ⅰ t),lissamine green staining and scoring of the corneal and conjunctival epithelium in the mice were performed at the age of 4,8,12,16 and 20weeks.Five mice from each group were sacrificed and their corneas were obtained to measure the central corneal epithelium thickness and to count the number of conjunctival goblet cells.In addition,lymphocyte infiltration in the lacrimal gland of the mice was examined with hematoxylin-eosin staining.The uhrastructure of the corneal epithelial cells and microvilli were assessed by scanning electron microscopy.The use and care of the mice were approved by the Experimental Animal Care Committee of the Third Military Medical University.Results No sign of dry eye was seen in both the 4-week-old C57BL/6.NOD-Aec1Aec2 mice and 4-week-old C57BL/6J mice.The S Ⅰ t values in 8-week-old,12-week-old,16-week-old and 20 week-old mice from the experiment group were (2.7 ±0.9) mm,(2.5 ±0.8) mm,(1.8±0.6) mm and (1.9± 0.1) mm,respectively,showing a significant reduction in comparison with those of the control mice of the same age(all P＜0.01).The amount of lissamine green staining in the C57BL/6.NOD-Aec1Aec2 mice gradually increased with age,showing elevated scores in 12-week-old,16-week-old and 20-week-old mice in the experiment group(all P＜0.01).The central corneal epithelium thicknesses were(20.18±3.75)μm,(17.01 ±5.25) μm,(14.19±5.72) μm and(12.00±3.25) μm in the 8-week-old,12-week-old,16-week-old and 20-week-old C57BL/6.NOD-Aec1Aec2 mice,respectively,which were significantly lower than those of the C57BL/6Jmice of the same age (all P＜0.01).The numbers of conjunctival goblet cells were (8.2±2.4),(6.2±2.1),(6.1 ±2.2) and (4.1 ± 2.0) in the 8-week-old,12-week-old,16-week-old and 20-week-old C57 BL/6.NOD-Aec 1Aec2 mice,respectively,showing a gradual decrease with age and a significant decline in comparison with those of the C57BL/6Jmice of the same age(all P＜0.01).Lymphocyte infiltration in the lacrimal gland and destruction of gland ducts were seen by hematoxylin-eosin staining,and acinar abnormality aggravated with aging.Reduction of corneal epithelial cells and the number of microvilli were distinguished with aging under the scanning electron microscope.The fasting bloodglucose levels of the two groups were both less than 6.0 mmol/L,and no significant difference was found between them at any age(P=0.637,0.610,0.163,0.086,0.938).Conclusions C57BL/6.NOD-Aec1Aec2 mice develop dry eye spontaneously with aging.The course of disease and characteristics of dry eye in C57BL/6.NOD-Aec1Aec2mice is similar to human dry eye.The C57BL/6NOD-Aec1 Aec2 mouse is the perfect model to study the pathogenesis of dry eye.
ABSTRACT
Background Intracameral or intracorneal administration of amphotericin B (AMB) can achieve significant therapeutic efficacy in the treatment of recalcitrant fungal keratitis in cases that do not respond to conventional antifungal therapy. However, the ocular pharmacokinetics of the two routes of administration is unclear.Objective The goal of this study was to investigate the level of amphotericin B in cornea and aqueous humor of rabbits after administration of AMB via three different routes. Methods Forty-five healthy domestic rabbits were randomly divided into three groups. 1% amphotericin B of 10 μg was intrastromally or intracamerally injected into 15 rabbits, respectively,in group A and group B. Topical 0. 25% amphotericin B was topically administered to the eyes with corneal epithelial debridement (group C). Experimental animals were sacrificed and the corneas and aqueous humor samples were obtained for the detection of levels of amphotericin B at 30 minutes,6 hours, 1 day,3 and 7 days by high-performance liquid chromatography (HPLC). Results Calibration curves were linear over the range of 0. 10-100. 00 mg/L. The concentration of 0. 10 mg/L was the lowest quantifiable limit. The recovery of amphotericin B ranged from 89. 1% -95.7% from aqueous humor samples and 81.4% -83.6% from the cornea samples. After a single injection,effective drug levels were achieved and maintained for 7 days in cornea in group A, exceeding the minimum inhibitory concentration at which 90% of isolates are inhibited (MIC90) for a wide spectrum of fungi and molds with significant differences in comparison with group B and group C ( P＜0. 05 ). Effective drug levels were achieved in the aqueous humor in group B at 30 minutes after a single injection, but drug levels decreased dramatically within 6 hours. The evident differences were found between group B and group A or group C (P＜ 0.05). A considerable amount of amphotericin B was detected in the cornea and aqueous humor in group C within 1 day.Conclusion Effective high drug levels can be reached in rabbit cornea and aqueous humor after intrastromal and intracameral injection, respectively. Penetration of topical amphotericin B was greatly elevated after epithelial debridement.
ABSTRACT
Objective To observe the histopathologic and ultrastructural characteristics of cornea and adjacent conjunctiva in Mooren’s ulcer. Methods The samples of limbal and central cornea and adjacent bulbar conjunctiva taken from active Mooren’s ulcer after lamellar keratoplasty were cut into paraffin sections and ultrathin sections and observed by light and transmission electron microscopy. The samples taken from patients of a Terrien’s marginal degeneration and a bacterial corneal ulcer were used as controls. Results Chronic inflammation including lymphocytes and plasma cells infiltrating existed in bulbar conjunctiva and sclera of Mooren’s ulcer. Limbal corneal epithelium, Bowman’s membrane, anterior stroma and adjacent superficial sclera melted and the inferior stromal collagen disorganized. The epithelial basement membrane of ulcer progressive edge had been destroyed while the epithelium and stroma kept quiescent. Lymphocytes infiltrated in conjunctiva and corneal epithelium of Terrien’s marginal degeneration with normal epithelial basement membrane, while Bowman’s membrane was destroyed. The epithelial basement membrane of bacterial corneal ulcer was intact. Conclusion Bulbar conjunctiva may act as a local lymph node of Mooren’s ulcer. Epithelial basement membrane of Mooren’s ulcer may have some abnormality as it was invaded first during ulcer progressing and it’s valuable to have a further study.